Tire recapping machine



Jan. 14, 1941.

TIRE RECAPPING MACHINE Filed June 27, .1.958

4 2 Sheets-Sheet 1 www. mmm.

' Y INVENTOR HAPOL@ V. 4M/5.5.

H. v. JAMES I v 2,228,316

Jan. Y'14, 1941. H. v. JAMES TIRE REGAPPING MACHINE:V

2 sheets-sheet 2 Filed June 27, 1938 l INVENTOR. HARO/.0 V JAMES.

IIIHIIII. 'Hulrllll MMIII.

ATTORNEY.

Patented Jan. 14, 1941 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to' a tire recapping machine and has for its principal object the provision of a highly eilicient' devicev by' means' of which a complete new traction surface and tread design may'be placed upon worn tire casings and in which the entire renewed circumference will be cured evenly, uniformly, and simultaneously.

Another object of the invention is to provide an eflicient means for' obtaining a. uniform, outward, radial pressure against the casing'without the use of air bags or similar devices.

Other objects are: to provide amachine of this character in which various types and sizes of moldsmay be quickly and easily interchanged; to provide means for allowingthe' mold to be tightly closed upon the rebuilt treadstock; and to provide means for insulating the heated mold to. reduce the heat of the outer'housing of'the machine.

Other objects and advantages residein the detail construction of the invention, which is designed for simplicity, economy, and. eiiiciency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawings which forms a part hereof. Like numerals refer to like parts in all viewsof the drawings and throughout the description.

In the drawings:

Fig. 1 is a side view of the complete retreading device.

Fig. 2 is a detail section vthrough the upper portion thereof illustrating the locking link.

Fig. 3 is a vertical section taken on the line 3-3, Fig. 1.

Fig. 4 is a detail perspective view illustrating the toggle link construction.

Fig. 5 is a detail section through one of the inner pressure plates taken on the line 5`5, Fig. 4.

This recapping device is intended for use in renewing the traction surface of worn tire casings and is to be used on casings on which the original design has worn away until traction efliciency and shock resistance have been reduced. It is not intended for use on casings in which the cords or fabric are exposed but only for producing a perfect union between the old tread remaining and the renewed cap thereon.

In using the improved capping' device, the old tread is sufficiently cleaned and buifed'to provide a perfect adhesion surface and is then built up with the new rubber. The casing with its raw rubber tread is then placed in this-M improved recapping machine which molds the new traction design thereon andcures the new tread to the remainder of the old tread on the casing. 5

The retreading device employs an outer housingformed of three sector-shaped, channel sections, a stationary section III, and two hinged sections II and I2. The hinged sections II and i I2 are mounted upon hinge pins* I3 at each ex- 19 tremity of the section I 0 and may be clamped together at thel top of the machine by means of a clamping link I4 and clamping lever I5.

'I'he lever` I5 is rotatably mounted at one extremity of the link I4 and engages an integral boss I6' formed on thev sectionv I2. The link I4 engages a similar boss II formed on the section II.

When the twosections are initially brought together around the tirek casing which is indicated on' the drawing at I8, the link and lever are in the broken line position of Fig. 2. By forcing the lever downwardly to the solid line position, the two sections are drawn and locked tight- 1y together. The fixed section Ill is formed with castj` feet I9 which rest upon, and are secured to, any suitable supporting stand or frame 2G.

The housing contains an annular series of tread molds 2| which are clamped in place in the hous- 30 ing by set screws 22 `and which are spaced from the periphery of the housing upon spacing pegs 23.

This construction allows an insulating air jacket to completely surround the molds and maintain them separated from and heat insulatedr from the housing. The series of tread molds2| is surrounded'loy an arcuate electrical heating element24 which is embedded in a peripheral channel around the entire series of molds. 40

The tire casing is forced radially outward into the molds 2| by means of a horizontal jack screw 25 which is supported concentrically of the housing in a suitable bearing bracket 26 extending from the supporting frame 20. The jack screw is 45 provided with a. hand wheel 2'I by means of which it may be rotated and it is threaded at opposite sides of the housing with threads of opposite hand. A nut member 28 rides on each set of threads on the screw 25.

It can be seen that as the screw is rotated one direction, the nut members 28 will approach each other and when rotated in the other direction they will separate from each other.

A series of toggle links 29 extend radially out- 55 l of links 29 are pivoted in a cross head 3| upon suitable hinge pins 32 which act to maintain the gear segments in mesh.

A pressure shoe 33 is mounted upon each cross head 3l. Each pressure shoe 33 is formed with a lug 34 which extends into a bifurcation in the cross head 3| and is pivoted therein upon a pivot bolt 35. One extremity of each pressure shoe is formed with an interlocking tongue 36. The other extremity of each shoe is formed with a lip joint 3l to receive the tongue 36 of the adjacent shoe. 'Ihis lip joint and tongue arrangement forms the entire series of shoes into a continuous annular band which acts against `a cushion ring 38 to force the tire radially outward against the annular series of molds 2|. The cushion ring 38 is simply a relatively heavy circular pad of resilient rubber which forms a peripheral tire around the .entire series o pressure shoes.

It can be seen that when the hand. wheel is rotated in one direction, the nut members 28will be brought together to force the pressure shoes 33 uniformly outward in all directions against the tire casing so Athat the latter is forced into uniform contact with the molds at all points.

To remove the retreaded casing, it is only necessary to reverse the hand wheel so as to draw the pressure shoes radially inward; release the locking link l to open the housing and thence slip the casing and cushion ring from the shoes. The `cushion lring can then be removed from the casing.

40 It win be noted that the original adhesion between the tread rubber :and the'cords is not disturbed. Heat is :applied only to the new stock vwith the exception of a small amount which is radiated to the side Wall by retaining flanges 5 39, which extends along each side of the molds 2 l. to hold the new rubber in confinement thereon.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied,

0 within the scope of the appended claims, with.-

out departing from the spirit of the invention.

Having thus described the invention', whatI is claimed and desired secured by Letters Patent is:

1. Means vfor .uniformly expanding a tire oasing within an annular recapping mol-d, comprisshoe, s'ad crossheads lying transversely of said shoes and being pivotally se'cured thereto so as to allow the shoes to rock in a plane at right angles to the axis of said series; a jack screw having oppositely threaded extremities; means for rotatively supporting said screw axially through said series of shoes; a nut on each extremity of sai-d screw on opposite sides of the plane of said series; toggle arms extending from each nut to the opposite extremities of said `eroSs heads; and means for causing said arms to expand in unison as said shaft i-s rotated.

2. Means for uniformly expanding a tire casing lwithin an annular recapping mold, comprising: an annular series of arcuate pressure shoes; a tongue on each shoe extending into a lip joint in an adjacent shoe to maintain the shoes in alignment; a lug extending radially inward from each pressure shoe and lying in a plane at right angles to the axis of the annular series; a cro-ss head within each pressure shoe, said cross heads lying transversely of said shoes and being provided with channels for the reception of said lugs; a pivot member securing each lug in its channel so as to allow Ithe shoes to rock ina plane at right angles to the axis of said series; a jack screw having oppositely threaded extremities; means for rotatively supporting said screw axially through said series ofA shoes; a nut on each extremity of said screw on opposite sides of the plane of said series; toggle arms extending from each nut to the opposite extremities of said cross heads; and means for causing said arms to expand in unison asvsaid shaft is rotated; an-d a solid expansilble rubber ring member surrounding said series Vof shoes to .be expanded thereby.

3. Means for uniformly expanding a tire lcasing within an annular recapping mold, comprising: an annular series of arcuate pressure shoes; a tongue on each shoe extending into alip joint in an adjacent s'hoe to maintain the shoes in alignment; :a lug extending radially inwardfrom each pressure` shoe; a cross'heaid within each pressure shoe, said cross heads lying transversely of said shoes .and being pivotedl on said lugs so as to al-lofw the shoes to rockin a plane at right angles to the axis of said `seriespa jack screw having oppositely threaded extremities; means for rotatively supporting said screw axially through said series of shoes; a nut on each extremity of said screw on opposite sides oi Ithe plane of said series; toggle arms extending from each nut to the opposite extremities of said cross heads; a toothed sector on each arm, the sectors of the adjacent arms on each cross head being intermeshed to cause Ithem toturn in unison.

HARQLD V. JAMES. 

